Very interesting hypothesis on the thought they have already been working. If they were mining ETH and selling them on the market, then it could make sense given the decrease in price in the same time period. The interesting thing about the tech sector is that the community will figure out a solution to avoid a centralization of miners for the benefit and security of the network. It would be interesting to see what the Ethereum community would do from here. Either way, PoW based assets will have to think about this as quantum computing becomes closer to reality.